A commonly used type of contact terminal comprises a stamped and formed conductive metal cylindrical socket which is dimensioned to receive a cylindrical pin. Contact terminals of this type are widely used, often in multicontact electrical connectors and are also used in connectors containing only one or two terminals.
Contact sockets of this type must be dimensioned such that when the pin is inserted into the socket, a contact force will be exerted by the socket on the pin to form a stable electrical connection. Frequently, a separate contact spring is mounted on the socket and when the pin is inserted into the socket, the spring is deflected and forces the surface of the pin against the surface of the contact. In order to obtain a stable electrical connection between an inserted pin and a socket, it is desirable that the contact spring should exert a relatively high force on the contact. However, the higher the contact force exerted by the spring on the pin, the greater the force required to insert the pin into the socket, in other words, the greater the insertion force required to mate the pin with the socket. High insertion forces are not desirable in pin-and-socket type contacts and, as a result, such contact terminals quite often represent a compromise design which has an acceptable insertion force requirement coupled with an acceptable contact force in the coupled contact pair. The present invention is directed to the achievement of an improved contact socket which is capable of exerting a relatively high contact force on an inserted pin and which does not require an unduly high insertion force when it is mated with the contact pin.